The BAFF/APRIL system: emerging new and unappreciated biomarkers in autoimmunity

Belimumab, a new drug targeting a molecule named BAFF, is efficient in some patients suffering from an incurable illness called lupus. No tool is available enabling physicians to select patients who could benefit from belimumab. BAFF and/or related molecules, found in the blood or urine of patients, are associated with activity of lupus and a related illness called primary Sjögren’s syndrome. Specific associations of BAFF and other molecules were found with lupus manifestations involving kidney, joints, skin or brain. Ethnicity appears to influence some of these associations. Combining measurement of molecules may help selecting patients who may benefit from belimumab, or define new molecule(s) to target.